The present invention relates to endoscopes or fiberscopes and, in particular, relates to such scopes having elongated flexible fiber optic bundles for imaging and illuminating remote objects in medical, veterinary, and industrial applications.
Representative examples of prior art scopes are shown and described in U.S. Pat. Nos. 4,277,168 and 4,745,908 issued Jul. 7, 1981 and May 24, 1988 to Toshio Oka and John L. Wardle, respectively.
The '168 patent deals with a mechanical device 12--12 connected to Wires 11--11 for positively twisting the distal end 1 of a flexible sheath 2 relative to a grip end 3. By means of a fixed guide tube 9 with an internal mark 16, the direction and angle of rotation of the distal end relative to the guide tube are detected optically to avoid damage at the distal end because of excessive torquing.
The '908 patent shows a scope with a wire braid sheath 67 for torque stabilizing so as to maintain registering between control head 4 and objective head 6.
While the above devices are operative, they do not show or suggest elongated flexible fiber optic bundles free to rotate to any degree in response to torque or twisting stresses with subtle or ingenious means incorporated into a distal end of a scope for indicating very clearly the rotational orientation of the distal end of the scope relative to a known bench mark or pointer.